Proper exception management

This commit updates the service to throw dedicated exception types for
common user error and associates proper HTTP status codes to them.

Fixes gh-38

initializr/src/main/groovy/io/spring/initializr/InitializrException.groovy

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2012-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.initializr
+
+import groovy.transform.InheritConstructors
+
+/**
+ * Base Initializr exception.
+ *
+ * @author Stephane Nicoll
+ * @since 1.0
+ */
+@InheritConstructors
+class InitializrException extends RuntimeException {
+}

initializr/src/main/groovy/io/spring/initializr/InvalidInitializrMetadataException.groovy

@@ -25,7 +25,6 @@ import groovy.transform.InheritConstructors
  * @since 1.0
  */
 @InheritConstructors
-class InvalidInitializrMetadataException extends RuntimeException {
-
+class InvalidInitializrMetadataException extends InitializrException {
 }
 

initializr/src/main/groovy/io/spring/initializr/InvalidProjectRequestException.groovy

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2012-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.initializr
+
+import groovy.transform.InheritConstructors
+
+import org.springframework.http.HttpStatus
+import org.springframework.web.bind.annotation.ResponseStatus
+
+/**
+ * Thrown when a {@link ProjectRequest} is invalid.
+ *
+ * @author Stephane Nicoll
+ * @since 1.0
+ */
+@InheritConstructors
+@ResponseStatus(HttpStatus.BAD_REQUEST)
+class InvalidProjectRequestException extends InitializrException {
+}

initializr/src/main/groovy/io/spring/initializr/ProjectRequest.groovy

@@ -57,7 +57,7 @@ class ProjectRequest {
 			def dependency = metadata.getDependency(it)
 			if (dependency == null) {
 				if (it.contains(':')) {
-					throw new IllegalArgumentException("Unknown dependency '$it' check project metadata")
+					throw new InvalidProjectRequestException("Unknown dependency '$it' check project metadata")
 				}
 				log.warn("No known dependency for style '$it' assuming spring-boot-starter")
 				dependency = new InitializrMetadata.Dependency()

initializr/src/main/groovy/io/spring/initializr/web/MainController.groovy

@@ -104,7 +104,7 @@ class MainController extends AbstractInitializrController {
 		upload(download, dir, generateFileName(request, 'zip'), 'application/zip')
 	}
 
-	@RequestMapping(value='/starter.tgz', produces='application/x-compress')
+	@RequestMapping(value = '/starter.tgz', produces = 'application/x-compress')
 	@ResponseBody
 	ResponseEntity<byte[]> springTgz(ProjectRequest request) {
 		def dir = projectGenerator.generateProjectStructure(request)
@@ -112,7 +112,7 @@ class MainController extends AbstractInitializrController {
 		def download = projectGenerator.createDistributionFile(dir, '.tgz')
 
 		new AntBuilder().tar(destfile: download, compression: 'gzip') {
-			zipfileset(dir:dir, includes:'**')
+			zipfileset(dir: dir, includes: '**')
 		}
 		upload(download, dir, generateFileName(request, 'tgz'), 'application/x-compress')
 	}

initializr/src/test/groovy/io/spring/initializr/ProjectRequestTests.groovy

@@ -73,7 +73,7 @@ class ProjectRequestTests {
 
 		request.style << 'org.foo:acme' // does not exist and
 
-		thrown.expect(IllegalArgumentException)
+		thrown.expect(InvalidProjectRequestException)
 		thrown.expectMessage('org.foo:acme')
 		request.resolve(metadata)
 	}

initializr/src/test/groovy/io/spring/initializr/web/MainControllerIntegrationTests.groovy

@@ -30,6 +30,7 @@ import org.springframework.http.HttpStatus
 import org.springframework.http.ResponseEntity
 import org.springframework.test.context.ActiveProfiles
 import org.springframework.util.StreamUtils
+import org.springframework.web.client.HttpClientErrorException
 
 import static org.junit.Assert.*
 
@@ -39,6 +40,9 @@ import static org.junit.Assert.*
 @ActiveProfiles('test-default')
 class MainControllerIntegrationTests extends AbstractInitializrControllerIntegrationTests {
 
+	private final def slurper = new JsonSlurper()
+
+
 	@Test
 	void simpleZipProject() {
 		downloadZip('/starter.zip?style=web&style=jpa').isJavaProject().isMavenProject()
@@ -140,8 +144,23 @@ class MainControllerIntegrationTests extends AbstractInitializrControllerIntegra
 	}
 
 	private def metricsEndpoint() {
-		def slurper = new JsonSlurper()
-		slurper.parseText(restTemplate.getForObject(createUrl('/metrics'), String))
+		parseJson(restTemplate.getForObject(createUrl('/metrics'), String))
+	}
+
+	@Test
+	void missingDependencyProperException() {
+		try {
+			invoke('/starter.zip?style=foo:bar')
+		} catch (HttpClientErrorException ex) {
+			def error = parseJson(ex.responseBodyAsString)
+			assertEquals HttpStatus.BAD_REQUEST, ex.getStatusCode()
+			assertTrue 'Dependency not in error message', error.message.contains('foo:bar')
+		}
+
+	}
+
+	private def parseJson(String content) {
+		slurper.parseText(content)
 	}
 
 	@Test
@@ -212,13 +231,17 @@ class MainControllerIntegrationTests extends AbstractInitializrControllerIntegra
 	}
 
 
+	private byte[] invoke(String context) {
+		restTemplate.getForObject(createUrl(context), byte[])
+	}
+
 	private ProjectAssert downloadZip(String context) {
-		def body = restTemplate.getForObject(createUrl(context), byte[])
+		def body = invoke(context)
 		zipProjectAssert(body)
 	}
 
 	private ProjectAssert downloadTgz(String context) {
-		def body = restTemplate.getForObject(createUrl(context), byte[])
+		def body = invoke(context)
 		tgzProjectAssert(body)
 	}